1. Field of the Disclosure
Aspects of the present invention relate to a control method for an image forming apparatus using network communication.
2. Description of the Related Art
Conventionally, in order to use a setting customized by a user in any image forming apparatus, there is provided a personalization technique in which user data is managed by an external server (for example, as discussed in Japanese Patent Application Laid-Open No. 2011-146956). In order to save communication time for user authentication with the server which arises before the user data is reflected on the image forming apparatus, Japanese Patent Application Laid-Open No. 2011-146956 discusses a technique in which the image forming apparatus acquires the user data from the server in advance at the timing when a user is not operating the image forming apparatus.
In a case where the user data managed by the server is applied to a number of image forming apparatuses installed in various places, the server may be disposed on the Internet. In such a case, in general, a firewall is disposed between the image forming apparatus and the Internet to take security thereof into consideration. When the above described personalization technique is realized, communication using a polling in which the image forming apparatus within the firewall requests the server on the Internet to transmit user data and acquires the user data is performed. However, when the above method discussed in Japanese Patent Application Laid-Open No. 2011-146956 is realized by the communication using the polling, if the user data is changed on the server, the changed user data cannot be reflected on the image forming apparatus on a real time basis. Therefore, the server needs to wait for a request of user data that is made by the image forming apparatus after the change. In order to increase an update frequency of the user data, a polling interval needs to be shorter. However, in a case where a number of image forming apparatuses are managed, regardless of the presence or absence of a change in user data, there is a problem in that a load for the server to process the request is increased, and a communication load is also applied to the network.
A push type communication method, in which a server on the Internet performs communication by continuously maintaining communication connection with a client on the intra-network within the firewall while making a handshake from the client as a starting point, has been proposed. A protocol known as a WebSocket protocol can be given as an example of the push type communication method. With regard to the WebSocket protocol, the Internet Engineering Task Force (IETF) Request for Comments (RFC) 6455 can be employed as a reference.
Employing the above push type communication method enables the server to transmit user data to the image forming apparatus without causing the image forming apparatus to make a request of the user data. However, in the push type communication method, because the communication connection with the client is maintained by the server, in a case where a number of image forming apparatuses are managed, there arises a problem in which a processing load of the server becomes remarkably high according to the number of image forming apparatuses, or the resource thereof is used considerably.